The description of electromagnetic components and systems by electrical circuit models is indispensable for a wide range of applications: In the field of EMC, electrical circuit models are ideally suited for the detection of EMC coupling paths, which are very difficult to track for 3D geometries. In the field of numerical optimization techniques, electrical circuit models offer short simulation times and allow the coupling of the electromagnetic domain to other physical domains. In the field of power electronics, electrical circuit models describe energy dissipation due to parasitic electromagnetic interactions.

The construction of an equivalent electrical circuit model is in general cumbersome and less formalized than a description in terms of electromagnetic fields. No general and reliable technique for the automated construction of equivalent electrical circuit models exists. The aim of this thesis is the development of a technique that allows a fully automated construction of equivalent electrical circuit models from 3D geometry information. Instead of constructing the circuit directly from geometry data, our approach consists of reducing a field-theoretical model to an equivalent electrical circuit model. In this way, we exploit the generality of the field-theoretical approach, which can be applied for a wide range of geometries using state-of-the-art simulation techniques. The electromagnetic effects having the largest impact in the frequency range of interest are then used for the construction of the electrical circuit model. The circuit elements can be seen as condensed representations of these field-theoretical processes. The reduction process allows a very direct assessment of the accuracy of the electrical circuit model.